Erica Rappold

Cardiac safety of lapatinib: Pooled analysis of 3689 patients enrolled in clinical trials

OBJECTIVE To analyze the cardiac safety of lapatinib, an oral, reversible, tyrosine kinase EGFR (ERBB1) and HER2 inhibitor, using prospective data collected in 44 clinical studies. PATIENTS AND METHODS Lapatinib (as monotherapy or in combination) was administered to 3689 patients in studies conducted between January 5, 2001, and September 30, 2006. Left ventricular ejection fraction (LVEF) was prospectively evaluated via multiple-gated acquisition scan or echocardiography at screening, every 8 weeks during therapy, and at withdrawal. We analyzed cardiac events defined as symptomatic (grade 3 or 4 left ventricular systolic dysfunction according to the National Cancer Institute Common Terminology Criteria for Adverse Events) or asymptomatic (LVEF decreases > or = 20% relative to baseline and below the institutions lower limit of normal; no symptoms). RESULTS A study-defined cardiac event was reported in 60 patients (1.6%) previously treated with anthracyclines (n=12), trastuzumab (n=14), or neither (n=34). These prior treatments were associated with a 2.2%, 1.7%, and 1.5% incidence of cardiac events, respectively. In most patients (53 patients, 83%), events were not preceded by symptoms. Mean times to onset and duration of LVEF decrease were 13.0 and 7.3 weeks, respectively. The decrease in LVEF was rarely severe; the mean nadir was 43%. In 40 patients for whom outcome was determined, 35 (88%) had a partial or full recovery regardless of continuation or discontinuation of lapatinib. No cardiac deaths occurred among patients treated with lapatinib. CONCLUSION Our review of data from 44 clinical studies revealed low levels of cardiotoxicity for lapatinib. Cardiac events were usually asymptomatic, caused reversible decreases in LVEF, and occurred at similar rates in patients who were and were not pretreated with anthracyclines or trastuzumab.

Adjuvant lapatinib for women with early-stage HER2-positive breast cancer: a randomised, controlled, phase 3 trial

BACKGROUND Worldwide, many patients with HER2-positive early stage breast cancer do not receive trastuzumab-the standard adjuvant treatment. We investigated the efficacy and safety of adjuvant lapatinib for patients with trastuzumab-naive HER2-positive early-stage breast cancer, started at any time after diagnosis. METHODS This study was a placebo-controlled, multicentre, randomised phase 3 trial. Women outpatients from 405 [corrected] centres in 33 countries [corrected] with HER2-positive early-breast cancer who had previously received adjuvant chemotherapy but not trastuzumab were randomly assigned (1:1) to receive daily lapatinib (1500 mg) or daily placebo for 12 months. Randomisation was done with a computer-generated sequence, stratified by time since diagnosis, lymph node involvement at diagnosis, and tumour hormone-receptor status. Investigators, site staff, and patients were masked to treatment assignment. The primary endpoint was disease-free survival in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT00374322. FINDINGS Between August, 2006, and May, 2008, 3161 women were enrolled and 3147 were assigned to lapatinib (n=1571) or placebo (n=1576). After a median follow-up of 47·4 months (range 0·4-60·0) in the lapatinib group and 48·3 (0·7-61·3) in the placebo group, 210 (13%) disease-free survival events had occurred in the lapatinib group versus 264 (17%) in the placebo group (hazard ratio [HR] 0·83, 95% CI 0·70-1·00; p=0·053). Central review of HER2 status showed that only 2490 (79%) of the randomised women were HER2-positive. 157 (13%) of 1230 confirmed HER2-positive patients in the lapatinib group and in 208 (17%) of 1260 in the placebo group had a disease-free survival event (HR 0·82, 95% 0·67-1·00; p=0·04). Serious adverse events occurred in 99 (6%) of 1573 patients taking lapatinib and 77 (5%) of 1574 patients taking placebo, with higher incidences of grade 3-4 diarrhoea (97 [6%] vs nine [<1%]), rash (72 [5%] vs three [<1%]), and hepatobiliary disorders (36 [2%] vs one [<1%]). INTERPRETATION Our data show that there was no significant difference in disease-free survival between groups when analysed in the intention-to-treat population. However, exploratory analyses restricted to patients who had HER2-positive disease confirmed by central fluorescence in-situ hybridisation review suggested marginal benefit with lapatinib in terms of disease-free survival. Thus lapatinib might be an option for women with HER2-positive breast cancer who do not or cannot receive adjuvant trastuzumab. FUNDING GlaxoSmithKline.

A randomized phase II study of the MEK1/MEK2 inhibitor trametinib (GSK1120212) compared with docetaxel in KRAS-mutant advanced non-small-cell lung cancer (NSCLC)

BACKGROUND KRAS mutations are detected in 25% of non-small-cell lung cancer (NSCLC) and no targeted therapies are approved for this subset population. Trametinib, a selective allosteric inhibitor of MEK1/MEK2, demonstrated preclinical and clinical activity in KRAS-mutant NSCLC. We report a phase II trial comparing trametinib with docetaxel in patients with advanced KRAS-mutant NSCLC. PATIENTS AND METHODS Eligible patients with histologically confirmed KRAS-mutant NSCLC previously treated with one prior platinum-based chemotherapy were randomly assigned in a ratio of 2 : 1 to trametinib (2 mg orally once daily) or docetaxel (75 mg/m(2) i.v. every 3 weeks). Crossover to the other arm after disease progression was allowed. Primary end point was progression-free survival (PFS). The study was prematurely terminated after the interim analysis of 92 PFS events, which showed the comparison of trametinib versus docetaxel for PFS crossed the futility boundary. RESULTS One hundred and twenty-nine patients with KRAS-mutant NSCLC were randomized; of which, 86 patients received trametinib and 43 received docetaxel. Median PFS was 12 weeks in the trametinib arm and 11 weeks in the docetaxel arm (hazard ratio [HR] 1.14; 95% CI 0.75-1.75; P = 0.5197). Median overall survival, while the data are immature, was 8 months in the trametinib arm and was not reached in the docetaxel arm (HR 0.97; 95% CI 0.52-1.83; P = 0.934). There were 10 (12%) partial responses (PRs) in the trametinib arm and 5 (12%) PRs in the docetaxel arm (P = 1.0000). The most frequent adverse events (AEs) in ≥20% of trametinib patients were rash, diarrhea, nausea, vomiting, and fatigue. The most frequent grade 3 treatment-related AEs in the trametinib arm were hypertension, rash, diarrhea, and asthenia. CONCLUSION Trametinib showed similar PFS and a response rate as docetaxel in patients with previously treated KRAS-mutant-positive NSCLC. CLINICALTRIALSGOV REGISTRATION NUMBER NCT01362296.

Prospective Validation of HLA-DRB1*07:01 Allele Carriage As a Predictive Risk Factor for Lapatinib-Induced Liver Injury

PURPOSE Liver injury is a serious adverse event leading to permanent discontinuation of lapatinib in affected patients. This study aimed to validate previously associated major histocompatibility complex (MHC) variants as predictors of risk of liver injury by using a large, randomized, placebo-controlled trial of lapatinib in human epidermal growth factor receptor 2-positive, early-stage breast cancer (Tykerb Evaluation After Chemotherapy [TEACH]: Lapatinib Versus Placebo In Women With Early-Stage Breast Cancer). PATIENTS AND METHODS The frequency of ALT elevation cases was compared among four MHC variants in 1,194 patients randomly assigned to lapatinib. Cumulative ALT elevation time courses during treatment were also compared between carriers and noncarriers of specified MHC variants. RESULTS In lapatinib-treated patients, there was a significant difference in ALT case incidence between HLA carriers and noncarriers. The highly correlated alleles HLA-DRB1*07:01 and HLA-DQA1*02:01 (study frequency, 22.4%) were associated with ALT elevation (odds ratio, 14) between cases (n = 37) and controls (n = 1,071). These associations strengthened at higher ALT elevation thresholds and in Hys Law cases. In lapatinib-treated patients, the overall risk for National Cancer Institute-Common Terminology Criteria for Adverse Events grade 3 ALT elevation (> 5× upper limit of normal) was 2.1%; HLA allele carriers had an increased risk of 7.7%; in noncarriers, risk was reduced to 0.5%, comparable to ALT elevation for all patients receiving placebo. The increase in ALT case incidence in the lapatinib arm showed no evidence of plateau during 1 year of lapatinib treatment. CONCLUSION These results validate HLA-DRB1*07:01 allele carriage as a predictor of increased risk of lapatinib-induced liver injury and implicate an immune pathology. The HLA association could support clinical management of patients experiencing hepatotoxicity during lapatinib treatment.

Identification of early breast cancer patient cohorts who may benefit from lapatinib therapy

In resource-constrained environments many patients with human epidermal growth factor receptor 2 (HER2)+ early breast cancer are currently not offered adjuvant anti-HER2 therapy. For patients who might be able to receive the tyrosine kinase inhibitor (TKI) lapatinib (e.g. after patent expiration), it is important to identify subgroups of patients for whom anti-HER2 TKI therapy could be beneficial. To do this, we used data from 2489 patients with centrally confirmed HER2+ disease enrolled in the adjuvant Tykerb Evaluation After Chemotherapy (TEACH) trial, investigating the effect of lapatinib in patients with HER2+ early breast cancer not treated with trastuzumab. We performed subgroup analyses and number-needed-to-treat (NNT) calculations using patient and tumour associated predictors. Hormone receptor negative (HR-) patients on lapatinib had a significantly prolonged disease-free survival (DFS) compared to HR- patients on placebo (hazard ratio 0.64, P=0.003). For patients with HR- disease, starting treatment with lapatinib ≤1 year from diagnosis improved DFS by 12.1% [2.1-22.1] at 2 years and 15.7% [4.1-27.2] at 5 years. Depending on lymph node status and time since diagnosis the NNT for recurrence (at 5 years) was between 5.9 (node positive patients <1 year from diagnosis) and 15.9. These numbers are in range with numbers reported for up-front adjuvant trastuzumab for HR unselected patients (e.g. 15.6 for DFS at 4 years in HERA). In a subgroup analysis of the adjuvant TEACH trial, we show that anti-HER2 monotherapy with a TKI is beneficial as adjuvant therapy in a subgroup of patients. NNT in HER2+ HR- patients are in range with those reported from up-front adjuvant trastuzumab trials.

Health related quality of life of women in TEACH, a randomised placebo controlled adjuvant trial of lapatinib in early stage Human Epidermal Growth Factor Receptor (HER2) overexpressing breast cancer

BACKGROUND To evaluate health related quality of life (HRQOL) in TEACH, a phase III randomized placebo controlled trial of 12 months of adjuvant lapatinib in HER2 positive (HER2+) early breast cancer which demonstrated marginal benefit in disease-free survival. METHODS Women on TEACH completed the Short Form 36-item health survey (version2; SF-36v2) at the baseline, six and 12 months after therapy initiation and six monthly thereafter. Mean changes were compared between treatment groups for two summary measures (Physical and Mental Component Summary scores; PCS and MCS) and eight domain measures (physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional and mental health), and in patients discontinuing therapy. A five-point change was deemed a Minimally Clinically Important Difference (MCID). Response analysis compared the proportion of patients demonstrating a MCID in HRQOL, and a regression analysis identified predictors of worsening HRQOL. FINDINGS 3074 (97%) subjects completed baseline SF-36v2. During the initial 12 months, summary SF-36v2 scores decreased in both arms but did not reach Minimally Clinically Important Difference (MCID) despite significant incidences of diarrhoea and rash in lapatinib treated patients. At six months, women receiving lapatinib had more significant reductions (p < 0.01 versus placebo) in social functioning. Early treatment discontinuations were more frequent on lapatinib (32% versus 18%), and were associated with more substantial decrements of HRQOL in both arms. For those discontinuing primarily due to adverse events, decrements in HRQOL reached MCID in Mental Summary scores (MCS) only. Lower baseline HRQOL was a significant predictor of worsening HRQOL (p < 0.05). INTERPRETATION Despite frequent but usually mild toxicities, adjuvant lapatinib is not associated with clinically significant decreases in overall HRQOL. These placebo-controlled results may also help to inform physicians and patients using lapatinib in metastatic HER2 positive breast cancer. FUNDING GlaxoSmithKline. The AVON Foundation NY supported PEG, DF and BM and The Friends of the Mater Foundation supported FB.

Rash in lapatinib-treated patients is not associated with human leukocyte antigen polymorphisms

Rash is a common side effect of lapatinib treatment. Since human leukocyte antigen (HLA) alleles have been implicated in multiple drug-induced cutaneous reactions, this study investigated the association of HLA alleles with lapatinib-induced rash. 1191 participants from a large lapatinib monotherapy trial underwent HLA genotyping, and allele carriage frequencies between rash cases and controls were compared. This analysis had adequate power to detect an association of common HLA alleles with rash, similar to those reported previously. No HLA alleles were significantly associated with lapatinib-induced rash, including the previously identified lapatinib hepatotoxicity biomarker HLA-DRB1*07:01 (p = 0.87). The present study is consistent with the view that lapatinib-induced rash is not the consequence of HLA-restricted, immune-mediated mechanisms.